Evolution and humans: big brain size uses energy (Evolution)

dhw: Some folk might say that 23 million years ago a pre-human “obviously” descended from the trees and indulged in a degree of land-dwelling that changed the form of its spine.

Not likely. This was an ancient monkey followed by other species of monkeys with a slight change in one lumbar vertebrae.

DAVID: We don't have the fossils to tell us how it happened, but with the 23 million year old evidence, and since I believe God speciates, they were changed so they could then descend.

dhw: There’s no such 23-million-year-old “evidence” beyond your totally unobvious “obviously”. But now we learn that since you believe God changed pre-humans in advance in order to speciate, God changed them in advance. They could just as easily have been “speciated” by descending from the trees and adapting their bodies to the new conditions.

Lucy obviously lived in and out of trees which fits your suggestion. But silverbacks and other great apes have done that for centuries without change. Lucy was something very different. God at work.

DAVID: First, you propose the early forms tried to think, and epigenetically forced an expansion of the brain. At a time when they did not know what they did not know, and lacked the capacity of imagining future possibilities.

dhw: What makes you believe that early forms couldn’t think? We have countless examples of our fellow animals solving new problems (and even making tools, although theirs do not require abilities beyond their existing physical capacities), so why shouldn’t pre-humans have had the same ability? No organism knows how to solve a problem before the problem arises, or before it has actually worked out the solution!

A non-answer. They could conceptualize to a certain level of compexity at each stage. The artifacts show what they could think of, and artifacts advance with jump in brain size.

DAVID: But the skull as bone is a different type of cells. Did the brain cell committees tell the skull cell committees what to do? It is the same chicken and egg problem that I've presented with larger brains, larger skulls and the required larger maternal birth canal in a changed pelvis. Requires foresight and design planning, none of which is epigenetic. God makes these changes in new species.

dhw: All anatomical changes require cooperation between DIFFERENT cell communities. And so instead of your God preprogramming this cooperation 3.8 billion years ago, or personally intervening and forcing the cells in each individual “pre-species species” to cooperate before necessary (= foresight and design planning), I propose a mechanism (perhaps invented by him) which enables them to do their own cooperating in response to need or opportunity. Whichever way, the different cell communities must cooperate, whether on a small or a large scale. According to you, they can do it by themselves to shrink the brain, but they can't do it to enlarge the brain.

You struggle to have cell communities doing their own thing, and bring in God to give them a mechanism to do so on their own, so He is never directly in charge. Intellectual side-step. If God created the universe, started life, managed evolution, then of course He speciated. As an agnostic you like to dabble a toe in holy waters.

DAVID: Generally, yes. They [ID-ers] believe in planning and design.
dhw: Of course intelligent design believers believe in planning and design. It’s the details of your divinely controlled evolutionary history I’m asking about. Do they insist, for instance, that their God dabbled with ape anatomy before apes left the trees?
DAVID: It fits their theories.

dhw: Ah, the master of evasion! Come on, admit it: Your “ID-friends” do not insist that their God dabbled with apes and whales BEFORE they descended from the trees or entered the water.